An electro-optical device is provided having an electro-optical panel and a case member, the electro-optical panel including a pair of substrates and a transparent member joined to at least one substrate of the pair of substrates, forming a structure which, in particular, allows the device to be made smaller and thinner, and the heat-dissipation capability to be increased in order to prevent overheating. A positioning section which accommodates one substrate of the pair of substrates, and which contacts an edge of the at least one substrate joined to the transparent member is provided in the case member accommodating the electro-optical panel.